Such valves are known for example from DE 10 2006 025 549 A1 and are used in application devices, for example spray guns, to control the flow of coating material.
The valve described in DE 10 2006 025 549 A1 is used in particular in electrostatically operating application devices. In such application devices the coating material is drawn electrostatically onto an article to be coated in that the application device is at a high electric potential, whereas the article to be coated is at frame potential.
The sealing element of the valve cooperates with a valve seat, which it closes or releases when the valve spindle in the valve housing takes up its closed position or its release position. The valve spindle in this case takes up its closed position as a rule under initial tension; a switchover between the closed position and the release position of the valve spindle is effected in known valves by means of a pressure fluid in the form of compressed air, which as a rule is at a moderate working pressure of approximately 6 bar.
For the switchover between the closed position and the release position of the valve spindle generally short switching times are desirable, which in known valves are however not always achieved at the pressures employed.
It is therefore an object of the invention to provide a valve of the type described in the introduction that enables faster switchover times between the closed position and the release position of the valve spindle.